[Rd] a R_PV problem

On 06/05/2008 3:02 AM, pseudo wrote:
> Dear all,
>> When using gdb to debug my C code, I use R_PV to show the content of
> SEXP variables:
>> SEXP sexp; // it is a data.frame
> SEXP colNames = getAttrib(sexp, R_NameSymbol);
>> A strange thing is that after halting the program:
>> (gdb) p R_PV(colNames)
>> does not show the content of colNames. I am positive my code is right
> because if I insert "PrintValue(colNames);" in the c code, it will
> print the right value. My debug result shows that the variable
> "colNames" failed the "isObject" call. I am not sure whether this is a
> new feature or bug. Anyone can help?
Are you sure that getAttrib has been called? Depending on the
optimization level under which your code was compiled, instructions may
be re-ordered. gdb may show the instruction pointer after that line,
even though that line hasn't been run yet.
Duncan Murdoch